User:Abel/PersonalData.js

// License: GPL
// Indexeddb JavaScript 
console.log('Indb loading');

function IndexedDBContainer( ww	) {

	// suppress console.log, switch to true for debug
	var Debug_switch = false;
	
	// deterministic hash generator for creating user id#s from usernames, should be replaced by something more functional (guaranteed to be transitively different)
	hashCode = function(s) {
		if ( s == undefined) {
			s = '00'
		}
		var h = 0, l = s.length, i = 0;
		if ( l > 0 )
			while (i < l)
				h = (h << 5) - h + s.charCodeAt(i++) | 0;
			return h;
		};

	
		if ( ww.user != undefined ) {
// if user exists in object passed to constructor, get username		
			var self = ww.user.getName();
// create userid by hashing username
			var idgen = hashCode(self);																										
			debuglog(idgen);

// Take username for standard databasename format:
// Our current convention for personal databasename (separate dbname for each user)
			var PersonalDataDataBaseName = "PD.IO" + idgen + "Database";
			// Use username in user to get up to date version of self
// Blank object for personal data Record with id and username included
			this.CurrentPerson = {id: idgen, name: {user: self}, age: 0};
			debuglog(PersonalDataDataBaseName);
			debuglog(this.CurrentPerson);
		}

	// ADD MORE DOC

	// EnqueuePDIO a PDIOLocalDatabase:User database access function with modes
	// Externally accessible wrapper for Enquire with current user / db preloaded

	this.EnqueuePDIO = async function( sw, c1, c2, c3 ) {
		debuglog("enquing pdio db " + PersonalDataDataBaseName + " with user " + JSON.stringify(CurrentPerson));
		var k = await Enquire( PersonalDataDataBaseName, this.CurrentPerson, sw, c1, c2, c3 );
		return k;
	}

	// Enquire, a general purpose indexeddb update function with modes

	// Mode 'aggressive push':
	// parameter record is pushed to database, overwriting whatever is there

	// Mode 'checkin':
	// record is retrieved from database, parameter record is pushed if not found

	// Mode 'get record'
	// updates record given as argument

	// Mode 'update record' field1 field2 field3
	// retrieve record, make record.field1.field2 = field3, push back

	// Mode 'update record' field1 field2
	// retrieve record, make record.field1 = field2, push back

	// Mode 'remove from record' field1 
	// retrieve record, splice/delete record.field1, push back
	
	// Mode 'remove from record' field1 field2 
	// retrieve record, splice/delete record.field1.field2, push back

	async function Enquire( pddbname, record, sqitch, control_1, control_2, control_3 ) {
		return new Promise(
			function(resolve, reject) {

				var pddb = window.indexedDB.open(pddbname, 3);
				var inp_obj;

				pddb.onerror = function() {  
				    console.log("Warning: Access to IndexedDB for application has been rejected.");
				};

				// indexeddb internal mechanism for version tracking of schema
				pddb.onupgradeneeded = function(evt) {
					console.log('upgrading database');
					var db = pddb.result;
					var store = db.createObjectStore(pddbname, {keyPath: "id"});

						// shouldn't the index be the wiki.personaldata.io username? 

						var index = db.store.createIndex("NameIndex", ["id"]);
				};
				// Database successfully opened function.
				pddb.onsuccess = function(xy) {
					debuglog(pddb.result);
					debuglog(xy);
					var db = pddb.result;
					var tx = db.transaction(pddbname, "readwrite");
					var store = tx.objectStore(pddbname);
					var index = store.index("NameIndex");	

					// Get the original record from the db...
					var getRecord = index.get([record.id]);

					getRecord.onsuccess = function() {
							debuglog( "Record in database: \n <<");
							debuglog( getRecord.result );
							debuglog( ">>");
						// Essential recordAdd																													
						if ( sqitch === "aggressive push" ) {
	// Mode 'aggressive push':
	// parameter record is pushed to database, overwriting whatever is there
							inp_obj = record;
							store.put( inp_obj );
							return inp_obj;
						} else if ( sqitch === "checkin" ) {
	// Mode 'checkin':
	// record is retrieved from database, parameter record is pushed if not found
							if ( getRecord.result !== undefined ) {
								debuglog("getting from store");
								inp_obj = getRecord.result;
							} else {
								debuglog("overriding whatever in there");
								inp_obj = record;
								store.put(inp_obj);
							}

						} else {
	// Methods manipulationg the actual record come here
	// Update & Remove from
							// If we got the record from store, use that version to be manipulated
							if ( getRecord.result !== undefined ) {		
								inp_obj = getRecord.result;
								
								if ( sqitch === "get record" ) {
									
									debuglog("Getting record");
									// we will return later
									
								} 

								// endof onsuccess
							} else {

								debuglog("Record not found");

								if ( sqitch === "update record" ) {
									// Update record will use supplied copy to update it
									inp_obj = record;
								} else {
									if ( sqitch === "get record" ) {
										inp_obj = undefined;
									} else {
										return undefined;
									}
									// Remove from record will quit as record was not even found
									
								}
							}
						} 

						if ( sqitch === "update record" ) { // Record Update															
							if ( control_1 != undefined ) {
								if ( control_2 != undefined ) {
									if ( control_3 != undefined ) {

	// Mode 'update record' field1 field2 field3
	// retrieve record, make record.field1.field2 = field3, push back

										if ( inp_obj[ control_1 ] == undefined ) { inp_obj[ control_1 ] = (isNaN( control_2 )) ? {} : [] };
										inp_obj[ control_1 ][ control_2 ] = control_3;	// => "Bob"
										store.put(inp_obj);
									} else {

	// Mode 'update record' field1 field2
	// retrieve record, make record.field1 = field2, push back

										inp_obj[ control_1 ] = inp_obj[ control_1 ] || {};
										if ( Array.isArray( inp_obj[ control_1 ] ) ) {
											inp_obj[ control_1 ].push( control_2 );
										} else {
											inp_obj[ control_1 ] = control_2;
										}
										store.put(inp_obj);

									}
								} else {
									// Only one control defined. We will return that part of the record, and change nothing
									inp_obj = inp_obj[ control_1 ];
								}
							} else {

								// There's not even control_1, we will just return the record itself

							}
							debuglog("return 3")
							// return inp_obj;

						};

						if ( sqitch === "remove from record" ) { // Record Update															
							if ( control_1 != undefined ) {
								if ( control_2 != undefined ) {

	// Mode 'remove from record' field1 field2 
	// retrieve record, splice/delete record.field1.field2, push back
									
									if ( Array.isArray( inp_obj[ control_1 ] ) && !isNaN( control_2 ) ) {
										inp_obj[ control_1 ].splice( control_2, 1 );
									} else {
										delete inp_obj[ control_1 ][ control_2 ];
									}

								} else {

	// Mode 'remove from record' field1 
	// retrieve record, splice/delete record.field1, push back

									delete inp_obj[ control_1 ];
								}
							}
							store.put(inp_obj);
						}

	// We are past all methodic code, Async return						
	
						resolve( inp_obj );

					};
	
	// Indexeddb internal mechanism, close db
	
					tx.oncomplete = function() {
						debuglog("return 1")
						db.close();
					};
				};
				debuglog("return 0")

	// End of promise
	
			}).then( function(result) {
				debuglog("Mark 3");
				debuglog(result);
				return result;
			});
	}

	function debuglog( l0g ){
		if ( Debug_switch ) {
			console.log( l0g );
		}
	}
};